Survivors of a New Hampshire circus tent collapse that killed a 41-year-old father and his 8-year-old daughter described the experience as the most terrifying moment of their lives.

Robert Young of Concord, Vermont, and his daughter Annabelle were hit by collapsing tent infrastructure, including pipes, when a storm with 75-mph winds tore through the Lancaster Fairgrounds in New Hampshire Monday. The National Weather Service is characterizing the weather pattern a microburst.

New Hampshire State Fire Marshal J. William Degnan Tuesday said no authorities were involved in setting up the tent and that organizers did not obtain a "place of assembly" permit. Degnan said he is investigating the cause of the tent collapse, and looking into statutes that pertain to not obtaining a proper permit.

As the investigation continues, survivors are sharing harrowing stories about how they escaped from the structure.

Briana Shannon, who took 3-year-old Karter Shannon to the circus Monday, described a perfect start to the night, with a pony ride and some carnival snacks for the toddler. Shannon dragged her sister Gabrielle Lepine along, too.

It was Lepine who saved little Karter's life when the tent came crashing down around 5:45 p.m.

"As it started shaking, she [Lepine] said, 'we should run,'" Shannon said.